Seismic Performance Analysis Of Subway High-rise Structure With Thick Plate Transfer

In recent years,the growth of the national economy and the rapid development of science and technology accelerate the structural development of high-rise buildings in the city.Due to the differences in the requirements for the functions of the upper structure and the lower structure,the structural types of the two will be different,so the thick plate transfer layer can be set in the meantime.Thick plate transfer structure has been used in China,but the study of thick plate transfer structure is still on the surface,and the analysis of its seismic performance is not mature enough,and further research is needed.In this paper,the finite element simulation and low-cycle reciprocating test are combined to study the seismic performance of high-rise structures covered with thick plates in a metro area:(1)The FEA model of ETABS is established for the example of a thick plate conversion high-rise structure.The modal analysis is carried out.The calculation results of the software of Yingjian section and ETABS are compared,and the correctness of the ETABS model is proved.The response spectrum analysis and elastic time history analysis are carried out.The results show that the shear force and displacement angle between layers will change in the transition layer,and the results of different seismic waves are different from the response spectrum results.Therefore,it is meaningful to carry out the supplementary checking of elastic time history analysis.(2)Based on the original model of the structure,three groups of 11 models are established by changing the thickness of the transfer plate,the location of the transfer floor and the total height of the structure.The dynamic response of each model under rare earthquake is studied,and the laws of the natural vibration period,story displacement,story shear force and story displacement angle of the structure are analyzed.The results show that the increase of plate thickness has little effect on the natural vibration period,story shear force and inter story displacement angle of the structure;with the increase of the transfer floor position,the mutation degree of the structure at the transfer floor begins to decrease,and the base shear force of the structure decreases in varying degrees compared with the original structure;with the increase of the total height of the structure,the natural vibration period of the structure increases significantly;the height of each structure is the same The results show that the inter story displacement angle of each story increases to a great extent,and the higher the story is,the greater the difference between the two;the shear force of the upper structure of the transfer story at the same height also increases,but the shear force of the lower structure of the transfer story is almost the same,which indicates that although the number of standard stories of the upper structure is increased,the stress of the lower structure is less affected.(3)Pushover analysis is carried out under four conditions of two different lateral force distribution loading modes,and the structural parameters at performance points are analyzed.The results show that the capacity spectrum and demand spectrum curves meet each other to obtain performance points,and the structure has sufficient bearing capacity and ductility;the maximum inter layer displacement angle of each working condition meets the requirements of the specification,and the values are: 1/545,1/545,1/623 and 1/633;the deformation of the frame hinge at the functional point and before the structure is in b-io state,which meets the requirements of large earthquake and not bad,and both directions The maximum ductility coefficient of frame hinge is 8.63 and2.45 respectively under earthquake action,and the ductility coefficient of the whole component is higher in X direction,which indicates that the ductility of the structure in Y direction is weaker than that in the X direction.(4)In order to further study the transfer thick plate,the low cycle reciprocating test is designed based on the model of an engineering example.A simplified model is established and its rationality is verified.Taking the 1 ～ 5 floors of the simplified model as the research object,a scale model with 1 / 5 similarity ratio is established.The loading design of the model meets the requirements of the base bending moment,the bending moment of the prototype structure,the bending moment of the base,the bending moment of the base and the bending moment of the base According to the similarity requirements of overturning moment and vertical load,the weak direction was loaded with 7 degree moderate earthquake and 8 degree moderate earthquake,and the difference of stress of different components of the structure was obtained;Although the strength of the reinforced concrete column at the thin plate is greater than that of the steel reinforced concrete column under the thick plate,the stiffness of the column at the thin plate is smaller,and the force distributed on the column is also smaller when the actuator applies the load,so the strain is smaller;It is found that the strain of the longitudinal reinforcement at the thick plate is small and the strain value is also low under the condition of 8 degree earthquake.It can be judged that the thick plate will not be damaged even under the condition of 8 degree earthquake.